Laser cutting: The horizontal laser beam emitted by the laser is turned into a vertically downward laser beam through a 45° total reflection mirror, and then focused by a lens to form a very small spot at the focus. When the spot is irradiated on the material, the material is made. It is quickly heated to the vaporization temperature, evaporating to form a hole, and as the beam moves against the material, and the auxiliary gas (carbon dioxide gas, oxygen, nitrogen, etc.) is blown away to melt the molten residue, so that the hole is continuously formed into a narrow width (such as About 0.1mm) slitting to complete the cutting of the material.
(1) Good cutting quality
1 .The laser cutting slit is narrow, the slits are parallel and perpendicular to the surface, and the dimensional accuracy of the cut parts can reach ±0.05mm.
2 .The cutting surface is smooth and beautiful, the surface roughness is only a few tens of microns, and even laser cutting can be used as the last process. No machining is required, and the parts can be used directly.
3 .After the laser is cut by the laser, the width of the heat-affected zone is small, the performance of the material near the slit is almost unaffected, and the deformation of the workpiece is small, the cutting precision is high, the geometry of the slit is good, and the shape of the slit cross-section is relatively regular. Rectangular. The comparison of laser cutting, oxyacetylene cutting and plasma cutting methods is shown in Table 1. The cutting material is a 6.2 mm thick low carbon steel plate.
(2) High cutting efficiency
Due to the transmission characteristics of the laser, the laser cutting machine is generally equipped with multiple numerical control worktables, and the entire cutting process can realize numerical control. During operation, it is only necessary to change the numerical control program to apply the cutting of different shapes of parts, which can perform two-dimensional cutting and three-dimensional cutting.
(3) Fast cutting speed
Cutting a 2mm thick low carbon steel plate with a power of 1200W, the cutting speed can reach 600cm/min; cutting a 5mm thick polypropylene resin plate, the cutting speed can reach 1200cm/min. The material does not need to be clamped during laser cutting.
(4) Non-contact cutting
There is no contact between the torch and the workpiece during laser cutting, and there is no tool wear. To machine parts of different shapes, there is no need to change the “tool”, just change the output parameters of the laser. The laser cutting process has low noise, low vibration and no pollution.
(5) There are many types of cutting materials
Compared with oxyacetylene cutting and plasma cutting, there are many types of laser cutting materials, including metal, non-metal, metal-based and non-metal matrix composites, leather, wood and fiber. However, for different materials, due to their different thermophysical properties and different absorption rates of laser light, different laser cutting adaptability is exhibited. The laser cutting performance of various materials is shown in Table 2 using a CO2 laser.